MainWindow.xaml:

<Window x:Class="TabControlBindSlide.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:TabControlBindSlide"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Window.Resources>
        <local:TestViewModel x:Key="vm"/>
        <Style TargetType="{x:Type Rectangle}">
            <Setter Property="Visibility" Value="Visible"/>
            <Setter Property="IsEnabled" Value="True"/>
            <Style.Triggers>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding  PreviousSelected }" Value="0"/>
                        <Condition Binding="{Binding ElementName=TestTabs, Path=SelectedIndex}" Value="1"/>
                    </MultiDataTrigger.Conditions>
                    <MultiDataTrigger.EnterActions>
                        <BeginStoryboard Name="MyBeginStoryboard1">
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetProperty="(Canvas.Left)" From="0" To="40" Duration="0:0:0.2"></DoubleAnimation>
                            </Storyboard>
                        </BeginStoryboard>
                    </MultiDataTrigger.EnterActions>
                    <MultiDataTrigger.ExitActions>
                        <RemoveStoryboard BeginStoryboardName="MyBeginStoryboard1" />
                    </MultiDataTrigger.ExitActions>
                </MultiDataTrigger>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding  PreviousSelected }" Value="0"/>
                        <Condition Binding="{Binding ElementName=TestTabs, Path=SelectedIndex}" Value="2"/>
                    </MultiDataTrigger.Conditions>
                    <MultiDataTrigger.EnterActions>
                        <BeginStoryboard Name="MyBeginStoryboard3">
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetProperty="(Canvas.Left)" From="0" To="75" Duration="0:0:0.2"></DoubleAnimation>
                            </Storyboard>
                        </BeginStoryboard>
                    </MultiDataTrigger.EnterActions>
                    <MultiDataTrigger.ExitActions>
                        <RemoveStoryboard BeginStoryboardName="MyBeginStoryboard3" />
                    </MultiDataTrigger.ExitActions>
                </MultiDataTrigger>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding  PreviousSelected }" Value="0"/>
                        <Condition Binding="{Binding ElementName=TestTabs, Path=SelectedIndex}" Value="3"/>
                    </MultiDataTrigger.Conditions>
                    <MultiDataTrigger.EnterActions>
                        <BeginStoryboard Name="MyBeginStoryboard5">
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetProperty="(Canvas.Left)" From="0" To="110" Duration="0:0:0.2"></DoubleAnimation>
                            </Storyboard>
                        </BeginStoryboard>
                    </MultiDataTrigger.EnterActions>
                    <MultiDataTrigger.ExitActions>
                        <RemoveStoryboard BeginStoryboardName="MyBeginStoryboard5" />
                    </MultiDataTrigger.ExitActions>
                </MultiDataTrigger>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding  PreviousSelected }" Value="1"/>
                        <Condition Binding="{Binding ElementName=TestTabs, Path=SelectedIndex}" Value="0"/>
                    </MultiDataTrigger.Conditions>
                    <MultiDataTrigger.EnterActions>
                        <BeginStoryboard Name="MyBeginStoryboard7">
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetProperty="(Canvas.Left)" From="40" To="0" Duration="0:0:0.2"></DoubleAnimation>
                            </Storyboard>
                        </BeginStoryboard>
                    </MultiDataTrigger.EnterActions>
                    <MultiDataTrigger.ExitActions>
                        <RemoveStoryboard BeginStoryboardName="MyBeginStoryboard7" />
                    </MultiDataTrigger.ExitActions>
                </MultiDataTrigger>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding  PreviousSelected }" Value="1"/>
                        <Condition Binding="{Binding ElementName=TestTabs, Path=SelectedIndex}" Value="2"/>
                    </MultiDataTrigger.Conditions>
                    <MultiDataTrigger.EnterActions>
                        <BeginStoryboard Name="MyBeginStoryboard9">
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetProperty="(Canvas.Left)" From="40" To="75" Duration="0:0:0.2"></DoubleAnimation>
                            </Storyboard>
                        </BeginStoryboard>
                    </MultiDataTrigger.EnterActions>
                    <MultiDataTrigger.ExitActions>
                        <RemoveStoryboard BeginStoryboardName="MyBeginStoryboard9" />
                    </MultiDataTrigger.ExitActions>
                </MultiDataTrigger>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding  PreviousSelected }" Value="1"/>
                        <Condition Binding="{Binding ElementName=TestTabs, Path=SelectedIndex}" Value="3"/>
                    </MultiDataTrigger.Conditions>
                    <MultiDataTrigger.EnterActions>
                        <BeginStoryboard Name="MyBeginStoryboard11">
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetProperty="(Canvas.Left)" From="40" To="115" Duration="0:0:0.2"></DoubleAnimation>
                            </Storyboard>
                        </BeginStoryboard>
                    </MultiDataTrigger.EnterActions>
                    <MultiDataTrigger.ExitActions>
                        <RemoveStoryboard BeginStoryboardName="MyBeginStoryboard11" />
                    </MultiDataTrigger.ExitActions>
                </MultiDataTrigger>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding  PreviousSelected }" Value="2"/>
                        <Condition Binding="{Binding ElementName=TestTabs, Path=SelectedIndex}" Value="0"/>

                    </MultiDataTrigger.Conditions>
                    <MultiDataTrigger.EnterActions>
                        <BeginStoryboard Name="MyBeginStoryboard13">
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetProperty="(Canvas.Left)" From="70" To="0" Duration="0:0:0.2"></DoubleAnimation>
                            </Storyboard>
                        </BeginStoryboard>
                    </MultiDataTrigger.EnterActions>
                    <MultiDataTrigger.ExitActions>
                        <RemoveStoryboard BeginStoryboardName="MyBeginStoryboard13" />
                    </MultiDataTrigger.ExitActions>
                </MultiDataTrigger>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding  PreviousSelected }" Value="2"/>
                        <Condition Binding="{Binding ElementName=TestTabs, Path=SelectedIndex}" Value="1"/>
                    </MultiDataTrigger.Conditions>
                    <MultiDataTrigger.EnterActions>
                        <BeginStoryboard Name="MyBeginStoryboard15">
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetProperty="(Canvas.Left)" From="70" To="40" Duration="0:0:0.2"></DoubleAnimation>
                            </Storyboard>
                        </BeginStoryboard>
                    </MultiDataTrigger.EnterActions>
                    <MultiDataTrigger.ExitActions>
                        <RemoveStoryboard BeginStoryboardName="MyBeginStoryboard15" />
                    </MultiDataTrigger.ExitActions>
                </MultiDataTrigger>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding  PreviousSelected }" Value="2"/>
                        <Condition Binding="{Binding ElementName=TestTabs, Path=SelectedIndex}" Value="3"/>
                    </MultiDataTrigger.Conditions>
                    <MultiDataTrigger.EnterActions>
                        <BeginStoryboard Name="MyBeginStoryboard17">
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetProperty="(Canvas.Left)" From="70" To="115" Duration="0:0:0.2"></DoubleAnimation>
                            </Storyboard>
                        </BeginStoryboard>
                    </MultiDataTrigger.EnterActions>
                    <MultiDataTrigger.ExitActions>
                        <RemoveStoryboard BeginStoryboardName="MyBeginStoryboard17" />
                    </MultiDataTrigger.ExitActions>
                </MultiDataTrigger>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding  PreviousSelected }" Value="3"/>
                        <Condition Binding="{Binding ElementName=TestTabs, Path=SelectedIndex}" Value="0"/>

                    </MultiDataTrigger.Conditions>
                    <MultiDataTrigger.EnterActions>
                        <BeginStoryboard Name="MyBeginStoryboard19">
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetProperty="(Canvas.Left)" From="110" To="0" Duration="0:0:0.2"></DoubleAnimation>
                            </Storyboard>
                        </BeginStoryboard>
                    </MultiDataTrigger.EnterActions>
                    <MultiDataTrigger.ExitActions>
                        <RemoveStoryboard BeginStoryboardName="MyBeginStoryboard19" />
                    </MultiDataTrigger.ExitActions>
                </MultiDataTrigger>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding  PreviousSelected }" Value="3"/>
                        <Condition Binding="{Binding ElementName=TestTabs, Path=SelectedIndex}" Value="1"/>
                    </MultiDataTrigger.Conditions>
                    <MultiDataTrigger.EnterActions>
                        <BeginStoryboard Name="MyBeginStoryboard21">
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetProperty="(Canvas.Left)" From="110" To="40" Duration="0:0:0.2"></DoubleAnimation>
                            </Storyboard>
                        </BeginStoryboard>
                    </MultiDataTrigger.EnterActions>
                    <MultiDataTrigger.ExitActions>
                        <RemoveStoryboard BeginStoryboardName="MyBeginStoryboard21" />
                    </MultiDataTrigger.ExitActions>
                </MultiDataTrigger>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding  PreviousSelected }" Value="3"/>
                        <Condition Binding="{Binding ElementName=TestTabs, Path=SelectedIndex}" Value="2"/>
                    </MultiDataTrigger.Conditions>
                    <MultiDataTrigger.EnterActions>
                        <BeginStoryboard Name="MyBeginStoryboard23">
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetProperty="(Canvas.Left)" From="110" To="70" Duration="0:0:0.2"></DoubleAnimation>
                            </Storyboard>
                        </BeginStoryboard>
                    </MultiDataTrigger.EnterActions>
                    <MultiDataTrigger.ExitActions>
                        <RemoveStoryboard BeginStoryboardName="MyBeginStoryboard23" />
                    </MultiDataTrigger.ExitActions>
                </MultiDataTrigger>
            </Style.Triggers>
        </Style>
    </Window.Resources>
    <Grid  DataContext="{StaticResource vm}" >
        <Grid.RowDefinitions>
            <RowDefinition Height="*"/>
            <RowDefinition Height="50"/>
        </Grid.RowDefinitions>
        <TabControl     SelectedIndex="{Binding Selected,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"     Grid.Row="0"   x:Name="TestTabs">
            <TabItem Name="Tab1" Header="News" />
            <TabItem Name="Tab2" Header="DLC" />
            <TabItem Name="Tab4" Header="Help" />
            <TabItem Name="Tab3" Header="Settings"/>
        </TabControl>
        <DockPanel  x:Name="rp" Grid.Row="0" LastChildFill="False" HorizontalAlignment="Stretch">
            <Canvas DockPanel.Dock="Left" >
                <Rectangle x:Name="Rect1" Fill="#ff0000" VerticalAlignment="Top"  Height="4" Margin="0,25,0,0" 
                           SnapsToDevicePixels="True" UseLayoutRounding="True" RenderOptions.EdgeMode="Aliased" 
                           Width="{Binding ElementName=TestTabs, Path=SelectedItem.ActualWidth}"  RenderOptions.BitmapScalingMode="HighQuality" />
            </Canvas>
        </DockPanel>
        <StackPanel Orientation="Horizontal" Grid.Row="1">
            <Label Content="selected" Width="100" Height="40" />
            <TextBox x:Name="sele" Text="{Binding Selected}" Width="100" Height="40" Background="AliceBlue" Margin="5"/>
            <Label Content="previousSelected"  Width="100" Height="40"/>
            <TextBox x:Name="prev" Text="{Binding PreviousSelected,Mode=OneWay}" Width="100" Height="40" Background="AliceBlue" Margin="5"/>
        </StackPanel>
    </Grid>
</Window>